Control method, device, medium and system of whole vehicle battery system

Abstract

The invention provides a control method, device, medium and system of a whole vehicle battery system. The method comprises the steps that under the condition that a compressor of the whole vehicle battery system starts liquid cooling work, the system temperature difference of the whole vehicle battery system is obtained, and a first system temperature difference is obtained; when the absolute value of the first system temperature difference is larger than or equal to the first system temperature difference threshold value, the compressor is controlled to stop working, and the first battery temperature difference is obtained; under the condition that the absolute value of the first battery temperature difference is greater than or equal to a first single-pack temperature difference threshold value, obtaining an interlayer temperature difference of the single battery to obtain a first interlayer temperature difference; and under the condition that the absolute value of the first interlayer temperature difference is greater than or equal to the first interlayer temperature difference threshold, reducing the interlayer temperature difference of the single battery by adopting a corresponding functional component. The problems that the judgment precision is low and the temperature difference of the system cannot be effectively reduced due to the fact that only the temperature difference between the battery packs is considered in temperature control of a whole vehicle battery system in an existing scheme are solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle battery systems. Specifically, it relates to a control method for a vehicle battery system, a control device for a vehicle battery system, a computer-readable storage medium, and a control system for a vehicle battery system. Background Art

[0002] During the application of the liquid cooling function in the vehicle battery system, due to factors such as the different installation positions of each single battery in the vehicle (which affects heat dissipation), different layouts of the liquid cooling pipes, and the battery structure in the power battery system, it is easy to cause a system temperature difference. When the system temperature difference is large, it affects the current driving use of the vehicle and the service life of the battery system. It is necessary to perform liquid cooling control to reduce the system temperature difference.

[0003] The temperature control of the existing vehicle battery system only considers the temperature difference between battery packs, resulting in low judgment accuracy and being unable to effectively reduce the system temperature difference. Summary of the Invention

[0004] The main purpose of the present application is to provide a control method for a vehicle battery system, a control device for a vehicle battery system, a computer-readable storage medium, and a control system for a vehicle battery system, so as to at least solve the problem that the temperature control of the existing vehicle battery system only considers the temperature difference between battery packs, resulting in low judgment accuracy and being unable to effectively reduce the system temperature difference.

[0005] To achieve the above object, according to one aspect of the present application, a control method for a vehicle battery system is provided. The method includes: when the compressor of the vehicle battery system starts to perform liquid cooling work, obtaining the system temperature difference of the vehicle battery system to obtain a first system temperature difference, where the liquid cooling work represents using the compressor to cool each battery pack in the vehicle battery system, and the system temperature difference is the difference between the maximum value of the temperature difference between the battery packs in the vehicle battery system and the minimum value of the temperature difference between the battery packs; when the absolute value of the first system temperature difference is greater than or equal to a first system temperature difference threshold, controlling the compressor to stop working, and obtaining the difference between the maximum value of the temperature difference between adjacent single batteries in the battery pack and the minimum value of the temperature difference between adjacent single batteries in the battery pack to obtain a first battery temperature difference; when the absolute value of the first battery temperature difference is greater than or equal to a first single-pack temperature difference threshold, obtaining the inter-layer temperature difference of the single battery to obtain a first inter-layer temperature difference, where the inter-layer temperature difference is the difference between the maximum value of the temperature difference between the upper layer and the lower layer of the single battery and the minimum value of the temperature difference between the upper layer and the lower layer of the single battery; when the absolute value of the first inter-layer temperature difference is greater than or equal to a first inter-layer temperature difference threshold, using a corresponding functional component to reduce the inter-layer temperature difference of the single battery, and the corresponding functional component is a component for adjusting the inter-layer temperature difference of the single battery.

[0006] Optionally, after reducing the inter-layer temperature difference of the single cell by using the corresponding functional component, the method further includes: acquiring the inter-layer temperature difference of the single cell again to obtain a second inter-layer temperature difference; when the absolute value of the second inter-layer temperature difference is less than or equal to a second inter-layer temperature difference threshold, acquiring the difference between the maximum temperature difference and the minimum temperature difference between adjacent single cells in the battery pack again to obtain a second battery temperature difference, where the second inter-layer temperature difference threshold is less than the first inter-layer temperature difference threshold; determining whether to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell according to the magnitude of the second battery temperature difference; when it is determined to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell, acquiring the system temperature difference of the vehicle battery system again to obtain a second system temperature difference; when the absolute value of the second system temperature difference is less than or equal to a second system temperature difference threshold, controlling the compressor to continue liquid cooling operation, where the second system temperature difference threshold is less than the first system temperature difference threshold.

[0007] Optionally, determining whether to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell according to the magnitude of the second battery temperature difference includes: when the absolute value of the second battery temperature difference is less than or equal to a second single-pack temperature difference threshold, determining to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell, where the second single-pack temperature difference threshold is less than the first single-pack temperature difference threshold; when the absolute value of the second battery temperature difference is greater than the second single-pack temperature difference threshold, determining that there is no need to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell.

[0008] Optionally, the method further includes: when the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, acquiring a first in-layer temperature difference, where the first in-layer temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the acquisition points within a single layer of the single cell; when the absolute value of the first in-layer temperature difference is greater than or equal to a first in-layer temperature difference threshold, controlling a heating module to heat the single layer of the single cell, and acquiring the difference between the maximum temperature difference and the minimum temperature difference between the acquisition points within the single layer of the single cell again to obtain a second in-layer temperature difference; when the absolute value of the second in-layer temperature difference is less than or equal to a second in-layer temperature difference threshold, acquiring the second battery temperature difference, where the second in-layer temperature difference threshold is less than the first in-layer temperature difference threshold.

[0009] Optionally, reducing the inter-layer temperature difference of the single cell by using the corresponding functional components includes at least one of the following: increasing the opening degree of the flow valve to adjust the inter-layer flow rate of the liquid cooling pipe of the vehicle battery system in the single cell, where the flow valve is located between the upper layer and the lower layer in the single cell; controlling the heating module to heat the single cell to perform heating compensation on the upper layer and the lower layer of the single cell, where the heating module is located between the upper layer and the lower layer in the single cell.

[0010] Optionally, before obtaining the system temperature difference of the vehicle battery system to obtain the first system temperature difference, it includes: obtaining multiple temperatures of the battery pack within a preset time period to obtain multiple battery pack temperatures; determining the current battery pack acquisition temperature of the battery pack according to the magnitudes of all the battery pack temperatures; determining the maximum temperature difference and the minimum temperature difference between the battery packs according to the current battery pack acquisition temperatures of all the battery packs.

[0011] Optionally, determining the current battery pack acquisition temperature of the battery pack according to the magnitudes of all the battery pack temperatures includes: sorting all the battery pack temperatures in chronological order to obtain a battery pack temperature sequence; when all the battery pack temperatures in the battery pack temperature sequence are the same, determining the battery pack temperature as the current battery pack acquisition temperature; when the first battery pack temperature in the battery pack temperature sequence is different from all the other battery pack temperatures in the battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are also different from each other, determining the first battery pack temperature as the current battery pack acquisition temperature; when the first battery pack temperature in the battery pack temperature sequence is different from all the other battery pack temperatures in the battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are the same, determining the other battery pack temperatures except the first battery pack temperature as the current battery pack acquisition temperature.

[0012] According to another aspect of the present application, there is provided a control device for a vehicle battery system, the device comprising: a first acquisition unit, configured to acquire a system temperature difference of the vehicle battery system, to obtain a first system temperature difference, when the compressor of the vehicle battery system starts to perform liquid cooling operation, the liquid cooling operation indicating that the compressor is used to cool each battery pack in the vehicle battery system, and the first system temperature difference being the difference between the maximum temperature difference and the minimum temperature difference among the battery packs in the vehicle battery system; a first processing unit, configured to control the compressor to stop working when the absolute value of the first system temperature difference is greater than or equal to a first system temperature difference threshold, and acquire the difference between the maximum temperature difference and the minimum temperature difference between adjacent single cells in the battery pack, to obtain a first battery temperature difference; a second acquisition unit, configured to acquire an interlayer temperature difference of the single cell, to obtain a first interlayer temperature difference, when the absolute value of the first battery temperature difference is greater than or equal to a first single pack temperature difference threshold, the interlayer temperature difference being the difference between the maximum value of the temperature difference between the upper layer and the lower layer of the single cell and the minimum value of the temperature difference between the upper layer and the lower layer of the single cell; a second processing unit, configured to reduce the interlayer temperature difference of the single cell by using a corresponding functional component when the absolute value of the first interlayer temperature difference is greater than or equal to a first interlayer temperature difference threshold, the corresponding functional component being a component for adjusting the interlayer temperature difference of the single cell.

[0013] According to still another aspect of the present application, there is provided a computer-readable storage medium, the computer-readable storage medium including a stored program, wherein, when the program runs, it controls the device where the computer-readable storage medium is located to execute any one of the methods.

[0014] According to yet another aspect of the present application, there is provided a control system for a vehicle battery system, the system comprising: one or more processors, a memory, and one or more programs, wherein, the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include those for executing any one of the methods.

[0015] Applying the technical solution of the present application, first, monitor the temperature difference of the system, that is, the temperature difference between battery packs in the entire battery system; if the first system temperature difference is greater than or equal to the first system temperature difference threshold, further check the temperature distribution within the battery pack; then, obtain the temperature difference between single cells in each battery pack. If the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, further analyze and control the temperature difference between battery layers and within the layers; measure the temperature difference between the upper and lower layers of the single cell; if the first inter-layer temperature difference is greater than or equal to the first inter-layer temperature difference threshold, use the corresponding functional component to reduce the inter-layer temperature difference of the single cell. It is precisely because the inter-layer temperature difference is considered that the judgment accuracy is improved, and further solves the problem that the temperature control of the vehicle-mounted battery system in the existing solution only considers the temperature difference between battery packs, resulting in low judgment accuracy and inability to effectively reduce the system temperature difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of the application. The illustrative embodiments of the application and their descriptions are used to explain the application and do not constitute an improper limitation to the application. In the drawings:

[0017] Figure 1 Shows a schematic flow chart of a control method for a vehicle-mounted battery system provided according to an embodiment of the present application;

[0018] Figure 2 Shows a schematic flow chart of a control method for a vehicle-mounted battery system provided according to an embodiment of the present application after using the corresponding functional component to reduce the inter-layer temperature difference of a single cell;

[0019] Figure 3 Shows a schematic flow chart of determining whether to stop using the corresponding functional component to reduce the inter-layer temperature difference of a single cell according to the magnitude of the second battery temperature difference provided according to an embodiment of the present application;

[0020] Figure 4 Shows a schematic flow chart of control based on the in-layer temperature difference of a single cell in a control method for a vehicle-mounted battery system provided according to an embodiment of the present application;

[0021] Figure 5 Shows a schematic flow chart of another control method for a vehicle-mounted battery system provided according to an embodiment of the present application;

[0022] Figure 6 Shows a block diagram of the structure of a control device for a vehicle-mounted battery system provided according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will describe the present application in detail with reference to the drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification, claims and the above-mentioned drawings of the present application are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of the present application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] As introduced in the background art, during the application process of the liquid cooling function of the vehicle battery system, due to factors such as the installation positions of individual battery packs in the vehicle (which affect heat dissipation), different layouts of liquid cooling pipes, and battery structures in the power battery system, it is easy to cause a system temperature difference. When the system temperature difference is large, it affects the current driving use of the vehicle and the service life of the battery system. It is necessary to perform liquid cooling control to reduce the system temperature difference. To solve the problem that the temperature control of the vehicle battery system in the existing solution only considers the temperature difference between battery packs, resulting in low judgment accuracy and inability to effectively reduce the system temperature difference, the embodiments of the present application provide a control method for a vehicle battery system, a control device for a vehicle battery system, a computer-readable storage medium, and a control system for a vehicle battery system.

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention.

[0028] In this embodiment, a control method for a vehicle battery system is provided. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0029] Figure 1 is a schematic flowchart of a control method for a vehicle battery system provided according to an embodiment of the present application. As Figure 1 shown, the method includes the following steps:

[0030] Step S101, when the compressor of the vehicle battery system starts to perform liquid cooling work, obtain the system temperature difference of the above vehicle battery system to obtain a first system temperature difference. The above liquid cooling work means using the above compressor to cool each battery pack in the above vehicle battery system. The above system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference among the above battery packs in the above vehicle battery system;

[0031] The calculation of the system temperature difference directly considers the highest and lowest points of the temperature distribution among the battery packs, which provides an accurate index for evaluating the uniformity of the overall battery system temperature. In liquid cooling control, temperature uniformity is the key to ensuring battery performance and extending battery life.

[0032] Step S102, when the absolute value of the above first system temperature difference is greater than or equal to the first system temperature difference threshold, control the above compressor to stop working, and obtain the difference between the maximum temperature difference and the minimum temperature difference among adjacent single cells in the above battery pack to obtain a first battery temperature difference;

[0033] By monitoring the temperature difference between adjacent single cells, the non-uniformity of the temperature distribution within the battery pack can be more accurately identified. This provides a more detailed basis for temperature control compared to only monitoring the temperature difference between battery packs, which helps to achieve temperature balance within the battery pack.

[0034] Step S103, when the absolute value of the above first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the inter-layer temperature difference of the above single cell to obtain a first inter-layer temperature difference. The above inter-layer temperature difference is the difference between the maximum value of the temperature difference between the upper and lower layers of the above single cell and the minimum value of the temperature difference between the upper and lower layers of the above single cell;

[0035] Traditional methods only focus on the temperature difference between battery packs and ignore the temperature difference between the upper and lower layers within the battery pack. By introducing the concept of inter-layer temperature difference, the present application can monitor and control the battery temperature at a finer level to ensure that not only the temperature between battery packs but also the temperature within the battery pack is in an ideal state.

[0036] Step S104, when the absolute value of the above first inter-layer temperature difference is greater than or equal to the first inter-layer temperature difference threshold, use the corresponding functional component to reduce the above inter-layer temperature difference of the above single cell. The above corresponding functional component is a component for adjusting the above inter-layer temperature difference of the above single cell.

[0037] In the above steps, first, the temperature difference of the monitoring system is monitored, that is, the temperature difference between battery packs in the entire battery system; if the first system temperature difference is greater than or equal to the first system temperature difference threshold, the temperature distribution within the battery pack is further checked; then, the temperature difference between individual cells within each battery pack is obtained. If the first cell temperature difference is greater than or equal to the first single-pack temperature difference threshold, the analysis and regulation of temperature differences are further carried out between and within battery layers; the temperature difference between the upper and lower layers of the above-mentioned individual cells is measured; if the first inter-layer temperature difference is greater than or equal to the first inter-layer temperature difference threshold, the corresponding functional components are used to reduce the above-mentioned inter-layer temperature difference of the individual cells. It is precisely because the inter-layer temperature difference is considered that the judgment accuracy is improved, and further the problem that the temperature control of the vehicle's entire battery system in the existing solution only considers the temperature difference between battery packs, resulting in a lower judgment accuracy and being unable to effectively reduce the system temperature difference is solved.

[0038] Among them, as Figure 2 shown, after using the corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the individual cells in step S104, the above method further includes the following steps:

[0039] Step S201, obtain the above-mentioned inter-layer temperature difference of the individual cells again to obtain the second inter-layer temperature difference;

[0040] Step S202, when the absolute value of the above-mentioned second inter-layer temperature difference is less than or equal to the second inter-layer temperature difference threshold, obtain the difference between the maximum temperature difference between adjacent individual cells in the above-mentioned battery pack and the minimum temperature difference between adjacent individual cells in the above-mentioned battery pack again to obtain the second cell temperature difference, and the above-mentioned second inter-layer temperature difference threshold is less than the above-mentioned first inter-layer temperature difference threshold;

[0041] Step S203, determine whether to stop using the above-mentioned corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the individual cells according to the magnitude of the above-mentioned second cell temperature difference;

[0042] Step S204, when it is determined to stop using the above-mentioned corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the individual cells, obtain the system temperature difference of the above-mentioned entire vehicle battery system again to obtain the second system temperature difference;

[0043] Step S205, when the absolute value of the above-mentioned second system temperature difference is less than or equal to the second system temperature difference threshold, control the compressor to continue liquid cooling operation, and the above-mentioned second system temperature difference threshold is less than the above-mentioned first system temperature difference threshold.

[0044] Specifically, the present application also provides a specific usage scenario for controlling the compressor to continue liquid cooling operation: In a race of a high-performance electric racing car, a double-layer power battery system is used. During the race, the vehicle needs to travel at high speeds, start and stop frequently, which will impose a huge thermal load on the battery system. The temperature management of the battery system is crucial for the performance and safety of the racing car.

[0045] Usage scenario process: At the initial stage of the race, the vehicle starts to accelerate, and the compressor starts liquid cooling operation to reduce the battery temperature to maintain the optimal working state of the battery; the battery management system continuously monitors the temperature difference between battery packs. When the absolute value of the detected first system temperature difference exceeds the preset first system temperature difference threshold (for example, the system temperature difference reaches 6°C), the system determines that the overall temperature distribution is unbalanced and more detailed temperature control is required; the system then enters the inter-layer temperature difference control stage and monitors the inter-layer temperature difference (the first inter-layer temperature difference) of each single battery. For example, the upper layer temperature of a certain single battery is 45°C, the lower layer temperature is 38°C, and the first inter-layer temperature difference is 7°C. If the absolute value of the first inter-layer temperature difference exceeds the first inter-layer temperature difference threshold (for example, set to 5°C), the system will adjust the opening of the flow valve, increase the coolant flow rate of the lower layer, or activate the heating film to heat-compensate the upper layer to narrow the inter-layer temperature difference; after the above adjustment, the system monitors the inter-layer temperature difference of this single battery again to obtain the second inter-layer temperature difference. If the absolute value of the second inter-layer temperature difference has dropped below the second inter-layer temperature difference threshold (for example, set to 2°C), this indicates that the inter-layer temperature control strategy has been effective; after the inter-layer temperature difference meets the conditions, the system further checks the temperature difference between single batteries within this battery pack to obtain the second battery temperature difference. If the absolute value of the second battery temperature difference is less than or equal to the second battery temperature difference threshold (for example, set to 3°C), it is considered that the temperature distribution between single batteries has also reached equilibrium; when the absolute value of the second system temperature difference is lower than the second system temperature difference threshold (for example, set to 4°C), it indicates that the temperature difference of the overall battery system has also been effectively controlled. At this time, the system determines that the compressor can be safely resumed to continue liquid cooling operation to further maintain the battery system within the optimal working temperature range.

[0046] Benefits of a specific usage scenario for controlling the compressor to continue liquid cooling operation: Precise temperature control ensures that the battery system remains in the optimal working state throughout the race, avoiding performance degradation caused by abnormal temperatures, enabling the racing car to maintain stable output during full-speed driving, and improving the race results; during high-speed races, excessive temperature differences may cause local overheating, leading to the serious consequence of battery thermal runaway. By precisely controlling the second inter-layer temperature difference and the second battery temperature difference, this risk can be effectively prevented, enhancing the safety of the racing car; the battery ages faster when operating at extreme temperatures. By continuously adjusting and controlling the battery temperature during the race, the damage to the battery caused by temperature fluctuations can be reduced, the service life of the battery system can be extended, and the maintenance cost can be reduced; through a hierarchical temperature control strategy, overusing cooling resources when not needed is avoided, thereby improving energy utilization efficiency and extending the endurance of the racing car.

[0047] Among them, as Figure 3 shown, step S203, that is, according to the magnitude of the above-mentioned second battery temperature difference, determining whether to stop using the above-mentioned corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the above-mentioned single battery, includes the following steps:

[0048] Step S301, when the absolute value of the above-mentioned second battery temperature difference is less than or equal to the second single-pack temperature difference threshold, it is determined to stop using the above-mentioned corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the above-mentioned single battery, and the above-mentioned second single-pack temperature difference threshold is less than the above-mentioned first single-pack temperature difference threshold;

[0049] Step S302, when the absolute value of the above-mentioned second battery temperature difference is greater than the above-mentioned second single-pack temperature difference threshold, it is determined that there is no need to stop using the above-mentioned corresponding functional components to reduce the above-mentioned inter-layer temperature difference of the above-mentioned single battery.

[0050] Specifically, when the absolute value of the second battery temperature difference is less than or equal to the second single-pack temperature difference threshold (a relatively small threshold), it indicates that the temperature distribution between layers and within layers has tended to be uniform. At this time, the system determines to stop using the corresponding functional components (such as electric flow valves, heating films, etc.) to further reduce the inter-layer temperature difference of the single battery. This can avoid over-intervention, save energy, and improve the overall operating efficiency of the system; conversely, if the absolute value of the second battery temperature difference is still greater than the second single-pack temperature difference threshold, it means that there is still a large imbalance in the internal temperature of the battery, and the system will continue to use the corresponding functional components for adjustment until the temperature difference drops to a safe range. This ensures the effectiveness and continuity of temperature control and avoids performance degradation and safety hazards caused by temperature imbalance.

[0051] In an embodiment of the present application, as Figure 4 shown, the above method further includes the following steps:

[0052] Step S401, when the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the temperature difference within the first layer. The temperature difference within the first layer is the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within a single layer of the single battery.

[0053] Step S402, when the absolute value of the temperature difference within the first layer is greater than or equal to the temperature difference threshold within the first layer, control the heating module to heat the single layer of the single battery, and obtain the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within the single layer of the single battery again to obtain the temperature difference within the second layer.

[0054] Step S403, when the absolute value of the temperature difference within the second layer is less than or equal to the temperature difference threshold within the second layer, obtain the second battery temperature difference. The temperature difference threshold within the second layer is less than the temperature difference threshold within the first layer.

[0055] Specifically, the present application also provides a specific usage scenario for controlling based on the temperature difference within a single battery layer: In a winter environment, the battery performance of an electric vehicle will be affected, especially during the charging process. Low temperature will not only reduce the charging efficiency but also exacerbate the temperature imbalance inside the battery, resulting in some battery cells being too cold and affecting their charging acceptance ability. In this case, the control of the temperature difference within a single battery layer inside the battery pack becomes particularly important.

[0056] When the electric vehicle is connected to the charging station and ready to charge, the BMS starts to monitor the temperature status of the battery system. If the absolute value of the first system temperature difference exceeds the first system temperature difference threshold (for example, the average system temperature difference exceeds 5°C), the system will first start the preheating program until the first system temperature difference returns to an acceptable range. When the first system temperature difference meets the standard, continue to monitor the temperature difference between adjacent single batteries inside the battery pack, that is, the first battery temperature difference. If the absolute value of this temperature difference is greater than or equal to the first single-pack temperature difference threshold (for example, the temperature difference between adjacent batteries exceeds 3°C), then further delve into the in-layer temperature control of the single battery. Obtain the temperature difference within a single layer of the single battery (the temperature difference within the first layer). Suppose within a certain single battery layer, the maximum acquisition point temperature is -5°C, the minimum acquisition point temperature is -10°C, and the temperature difference within the first layer is 5°C. If the absolute value of the temperature difference within the first layer exceeds the temperature difference threshold within the first layer (for example, the in-layer temperature difference threshold is 4°C), the system starts the heating module (such as a PI heating film) to heat the low-temperature area to reduce the in-layer temperature difference; after the heating module works for a period of time, obtain the temperature difference within the single battery layer again to obtain the temperature difference within the second layer. Suppose after heating, the maximum acquisition point temperature becomes 0°C, the minimum acquisition point temperature becomes -5°C, and the temperature difference within the second layer is reduced from 5°C to 2.5°C.

[0057] Benefits of a specific usage scenario for controlling based on the temperature difference within a single cell: By reducing the temperature difference within the single cell layer, the average temperature of the battery unit can be increased, thereby enhancing the charging reception ability, accelerating the charging speed, and improving the overall charging efficiency; reducing the temperature difference within the layer helps prevent uneven aging of the battery in a low-temperature environment, especially avoiding the accelerated aging of some battery units due to being overcooled, and extending the overall life of the battery system; an excessive temperature difference within the layer may cause local battery units to overheat or overcool, increasing safety hazards during the charging process; through timely heating regulation, these risks can be effectively reduced to ensure the safety of the charging process.

[0058] The PI heating film, whose full name is Polyimide heating film, is a heating module using polyimide as the base material. Polyimide is a high-performance thermosetting plastic with excellent heat resistance, electrical insulation, and mechanical strength, and is very suitable as the base material of the heating film in high-requirement environments.

[0059] In an embodiment of the present application, to reduce the above-mentioned inter-layer temperature difference of the above-mentioned single cell by using the above-mentioned corresponding functional components, it includes at least one of the following: adjusting the opening degree of the flow valve to adjust the inter-layer flow rate of the liquid cooling pipe of the above-mentioned vehicle battery system in the above-mentioned single cell, and the flow valve is located between the upper layer and the lower layer within the above-mentioned single cell; controlling the heating module to heat the above-mentioned single cell to perform heating compensation on the above-mentioned upper layer and the above-mentioned lower layer of the above-mentioned single cell, and the heating module is located between the upper layer and the lower layer within the above-mentioned single cell.

[0060] Specifically, adjusting the opening degree of the flow valve includes: determining the target inter-layer temperature range where the above-mentioned first inter-layer temperature difference is located, and the target inter-layer temperature range is one of all the preset inter-layer temperature ranges; determining the target power according to the first mapping relationship and the above-mentioned target inter-layer temperature range, and the first mapping relationship is the mapping relationship between the preset inter-layer temperature range and the preset power of the above-mentioned heating module; adjusting the power of the above-mentioned heating module to the above-mentioned target power to heat the above-mentioned single cell.

[0061] Controlling the heating module to heat the above-mentioned single cell includes: determining the target inter-layer temperature range where the above-mentioned first inter-layer temperature difference is located, and the target inter-layer temperature range is one of all the preset inter-layer temperature ranges; determining the target opening degree according to the second mapping relationship and the above-mentioned target inter-layer temperature range, and the second mapping relationship is the mapping relationship between the preset inter-layer temperature range and the preset opening degree of the above-mentioned flow valve; adjusting the opening degree of the above-mentioned flow valve to the above-mentioned target opening degree.

[0062] By determining the target interlayer temperature range in which the first interlayer temperature difference lies, the system can call the first mapping relationship and the second mapping relationship according to the current specific temperature conditions, and accurately calculate the required heating power and the opening degree of the flow valve. This method is more flexible than traditional fixed settings, can make optimal responses to different working conditions and battery states, and realizes highly refined temperature management. The determination of the target power and the target opening degree is based on real-time temperature data and the target interlayer temperature range, which ensures the efficient utilization of heating and liquid cooling resources. Compared with the extensive control strategy, this method can avoid unnecessary energy waste. Especially when the battery temperature is close to the ideal range, through precise power and opening degree adjustment, the energy consumption can be minimized and the overall energy efficiency of the system can be improved.

[0063] In an embodiment of the present application, before obtaining the system temperature difference of the above-mentioned vehicle battery system and obtaining the first system temperature difference, it includes: obtaining multiple temperatures of the above-mentioned battery pack within a preset time period to obtain multiple battery pack temperatures; determining the current battery pack acquisition temperature of the above-mentioned battery pack according to the magnitudes of all the battery pack temperatures; determining the maximum temperature difference between the above-mentioned battery packs and the minimum temperature difference between the above-mentioned battery packs according to the above-mentioned current battery pack acquisition temperatures of all the above-mentioned battery packs.

[0064] Specifically, for example, if the maximum temperature difference exceeds a preset system temperature difference threshold, the system will start a self-circulation mode or adjust the working state of the compressor to reduce the overall temperature difference of the system. If the minimum temperature difference is within the safe range, the system can maintain the current liquid cooling working state to avoid unnecessary energy consumption. By continuously monitoring and calculating the temperature difference between the battery packs, the system can timely identify and solve any temperature imbalance problems, ensuring a uniform temperature distribution throughout the battery system, which is a key factor for battery health and performance. Excessive temperature differences between battery packs may lead to thermal runaway, that is, the battery temperature rises rapidly, causing battery damage or even fire. Precise temperature difference monitoring and timely temperature adjustment strategies can significantly reduce the risk of thermal runaway and improve the safety of the system.

[0065] In an embodiment of the present application, determining the current battery pack acquisition temperature of the above battery pack according to the magnitudes of all battery pack temperatures includes: sorting all battery pack temperatures in chronological order to obtain a battery pack temperature sequence; when all the above battery pack temperatures in the above battery pack temperature sequence are the same, determining the above battery pack temperature as the above current battery pack acquisition temperature; when the first battery pack temperature in the above battery pack temperature sequence is different from all other battery pack temperatures in the above battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are also different from each other, determining the first battery pack temperature as the above current battery pack acquisition temperature; when the first battery pack temperature in the above battery pack temperature sequence is different from all other battery pack temperatures in the above battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are the same, determining the other battery pack temperatures except the first battery pack temperature as the above current battery pack acquisition temperature.

[0066] Specifically, the preset time period can be from 5 s to 30 s. When there are inconsistent temperatures in the battery pack temperature sequence, the system needs to further distinguish and process; if the first battery pack temperature is different from all the other battery pack temperatures in the sequence and the other battery pack temperatures are the same as each other, then the system determines the temperature value of the remaining battery packs as the current battery pack acquisition temperature, excluding the influence of the first outlier and ensuring the accuracy of temperature measurement. On the contrary, if the first battery pack temperature in the sequence is different from all other temperatures but the temperature values of the other battery packs are different from each other, the system will take the temperature of the first battery pack as the current battery pack acquisition temperature, which reflects a potential local temperature anomaly. Through the strategy of time series sorting and outlier exclusion, the system can more accurately identify and reflect the true temperature state of the battery pack, avoiding the possibility of misleading the entire battery temperature control system due to a single data point error. When the system detects local temperature inconsistency, it can quickly identify and take measures to avoid the spread of local overheating or overcooling phenomena, preventing potential safety hazards and performance degradation caused thereby. Based on the accurate current battery pack acquisition temperature information, the system can formulate a more refined temperature control strategy, such as adjusting the power of the heating module or the opening of the flow valve, to achieve the best temperature balance effect and improve the electric energy conversion efficiency and battery service life.

[0067] Explanation of the values of the first system temperature difference threshold, the first single-pack temperature difference threshold, the first inter-layer temperature difference threshold, the first intra-layer temperature difference threshold, the second system temperature difference threshold, the second single-pack temperature difference threshold, the second inter-layer temperature difference threshold, and the second intra-layer temperature difference threshold: The optimal operating temperature range and the extreme temperature range of the battery, for example, the optimal operating temperature of a general lithium-ion battery is between 20°C and 40°C; Analyze the impact of the battery's performance at different temperatures, such as capacity, charging efficiency, internal resistance, etc., to determine the point at which the negative impact of the temperature change triggering the temperature difference threshold on the battery's performance begins to appear. Through experimental testing of the battery's performance and life under different temperature difference conditions, record the performance changes of the battery from slight temperature difference to severe temperature difference, and find out the temperature difference points that have an obvious adverse impact on the performance, and use this as the basis for the threshold. Set lower first intra-layer temperature difference threshold and first inter-layer temperature difference threshold to detect potential uneven heating earlier, avoid local overheating, and thus enhance the safety of the system. Evaluate the impact of the temperature difference threshold on the long-term reliability and life of the battery. Generally speaking, a more stringent threshold setting (i.e., a lower temperature difference threshold) is beneficial to slowing down the battery aging process and extending the battery life. The first series of temperature difference thresholds (such as the first system temperature difference threshold, the first single-pack temperature difference threshold, etc.) are usually set more strictly to quickly respond to temperature imbalance situations that may damage the battery. The second series of temperature difference thresholds are slightly looser and are suitable for temperature management in daily operations to ensure good battery performance even in non-extreme situations.

[0068] Example of empirical values: The first system temperature difference threshold: May be set at about 5°C to ensure that the overall temperature difference of the system is not too large, affecting the battery performance and safety. The first single-pack temperature difference threshold: Considering the consistency of the batteries inside the single pack, it may be set at about 3°C. The first inter-layer temperature difference threshold: Given the direct impact of the inter-layer temperature difference on the battery life, it may be set between 2°C and 4°C to respond promptly to uneven inter-layer temperatures. The first intra-layer temperature difference threshold: To protect the battery cells, it may be set between 1°C and 2°C to prevent local overheating and cause safety problems. The second system temperature difference threshold: On the premise of ensuring the safety of normal operations, it may be relaxed to 7°C to 10°C, allowing a certain temperature difference fluctuation in the system under non-extreme conditions. The second single-pack temperature difference threshold: May be relaxed to about 5°C to reduce the frequent start of heating or cooling during daily use and save energy. The second inter-layer temperature difference threshold: Set between 3°C and 6°C, moderately relaxing the control of the inter-layer temperature difference while still paying attention to the battery health. The second intra-layer temperature difference threshold: May be relaxed to 2°C to 3°C, allowing a certain degree of temperature difference inside the layer under normal operating conditions while monitoring its changes.

[0069] To enable those skilled in the art to more clearly understand the technical solution of this application, the implementation process of the control method for the vehicle's battery system of this application will be described in detail below in conjunction with specific embodiments.

[0070] This embodiment relates to a specific control method for a vehicle's battery system. As Figure 5 shown, it includes:

[0071] When the compressor of the vehicle's battery system starts to perform liquid cooling work, obtain the system temperature difference of the vehicle's battery system to get the first system temperature difference. Liquid cooling work means using the compressor to cool each battery pack in the vehicle's battery system. The system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference among the battery packs in the vehicle's battery system.

[0072] When the absolute value ΔT1 of the first system temperature difference is greater than or equal to the first system temperature difference threshold T1, control the compressor to stop working, and obtain the difference between the maximum temperature difference and the minimum temperature difference between adjacent single cells in the battery pack to get the first battery temperature difference. When ΔT1 is less than T1, obtain the first system temperature difference again.

[0073] When the absolute value ΔT2 of the first battery temperature difference is greater than or equal to the first single - pack temperature difference threshold T2, obtain the inter - layer temperature difference of the single cell to get the first inter - layer temperature difference. The inter - layer temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the upper and lower layers of the single cell. When ΔT2 is less than T2, obtain the first battery temperature difference again.

[0074] When the absolute value ΔT3 of the first inter - layer temperature difference is greater than or equal to the first inter - layer temperature difference threshold T3, use the corresponding functional component to reduce the inter - layer temperature difference of the single cell. The corresponding functional component is the component that adjusts the inter - layer temperature difference of the single cell. When ΔT3 is less than T3, obtain the first inter - layer temperature difference again.

[0075] After using the corresponding functional component to reduce the inter - layer temperature difference of the single cell, obtain the inter - layer temperature difference of the single cell again to get the second inter - layer temperature difference. When the absolute value ΔT4 of the second inter - layer temperature difference is less than or equal to the second inter - layer temperature difference threshold T4, obtain the difference between the maximum temperature difference and the minimum temperature difference between adjacent single cells in the battery pack again to get the second battery temperature difference. The second inter - layer temperature difference threshold is less than the first inter - layer temperature difference threshold. When ΔT4 is greater than T4, obtain the second inter - layer temperature difference again.

[0076] When the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, it is also necessary to obtain the temperature difference within the first layer. The temperature difference within the first layer is the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within a single layer of a single battery. When the absolute value of the temperature difference ΔT5 within the first layer is greater than or equal to the temperature difference threshold T5 within the first layer, control the heating module to heat a single layer of the single battery, and again obtain the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within a single layer of the single battery to obtain the temperature difference within the second layer. When ΔT5 is less than T5, obtain the temperature difference within the first layer again. When the absolute value ΔT6 of the temperature difference within the second layer is less than or equal to the temperature difference threshold T6 within the second layer, obtain the second battery temperature difference. The temperature difference threshold within the second layer is less than the temperature difference threshold within the first layer. When ΔT6 is less than T6, obtain the temperature difference within the second layer again.

[0077] According to the magnitude of the second battery temperature difference, determine whether to stop using the corresponding functional components to reduce the inter-layer temperature difference of the single battery. Specifically, when the absolute value ΔT7 of the second battery temperature difference is less than or equal to the second single-pack temperature difference threshold T7, it is determined to stop using the corresponding functional components to reduce the inter-layer temperature difference of the single battery. The second single-pack temperature difference threshold is less than the first single-pack temperature difference threshold. When the absolute value ΔT7 of the second battery temperature difference is greater than the second single-pack temperature difference threshold T7, it is determined that there is no need to stop using the corresponding functional components to reduce the inter-layer temperature difference of the single battery.

[0078] When it is determined to stop using the corresponding functional components to reduce the inter-layer temperature difference of the single battery, obtain the system temperature difference of the vehicle battery system again to obtain the second system temperature difference. When the absolute value ΔT8 of the second system temperature difference is less than or equal to the second system temperature difference threshold T8, resume the liquid cooling operation of the compressor, that is, control the compressor to continue the liquid cooling operation. The second system temperature difference threshold is less than the first system temperature difference threshold.

[0079] In addition, using the corresponding functional components to reduce the inter-layer temperature difference of the single battery includes at least one of the following: increasing the opening degree of the flow valve to adjust the liquid cooling tube flow rate between the upper and lower layers of the single battery within the vehicle battery system. The flow valve is located between the upper and lower layers of the single battery; controlling the heating module to heat the single battery to perform heating compensation on the upper and lower layers of the single battery. The heating module is located between the upper and lower layers of the single battery.

[0080] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0081] The embodiment of the present application also provides a control device for a vehicle battery system. It should be noted that the control device for the vehicle battery system in the embodiment of the present application can be used to execute the control method for the vehicle battery system provided in the embodiment of the present application. This device is used to implement the above-mentioned embodiments and preferred implementation manners, and those that have been described will not be repeated. As used hereinafter, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0082] The following introduces the control device for the vehicle battery system provided in the embodiment of the present application.

[0083] Figure 6 It is a structural block diagram of a control device for a vehicle battery system according to an embodiment of the present application. As Figure 6 shown, the device includes:

[0084] A first acquisition unit 61, configured to obtain the system temperature difference of the vehicle battery system, to obtain a first system temperature difference, when the compressor of the vehicle battery system starts to perform liquid cooling work, where the liquid cooling work means using the compressor to cool each battery pack in the vehicle battery system, and the first system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference among the battery packs in the vehicle battery system; a first processing unit 62, configured to control the compressor to stop working when the absolute value of the first system temperature difference is greater than or equal to a first system temperature difference threshold, and obtain the difference between the maximum temperature difference and the minimum temperature difference between adjacent single cells in the battery pack, to obtain a first battery temperature difference; a second acquisition unit 63, configured to obtain the inter-layer temperature difference of the single cell, to obtain a first inter-layer temperature difference, when the absolute value of the first battery temperature difference is greater than or equal to a first single-pack temperature difference threshold, where the inter-layer temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the upper layer and the lower layer of the single cell; a second processing unit 64, configured to use a corresponding functional component to reduce the inter-layer temperature difference of the single cell when the absolute value of the first inter-layer temperature difference is greater than or equal to a first inter-layer temperature difference threshold, and the corresponding functional component is a component for adjusting the inter-layer temperature difference of the single cell.

[0085] In the above device, first, the temperature difference of the monitoring system is monitored, that is, the temperature difference between battery packs in the entire battery system; if the first system temperature difference is greater than or equal to the first system temperature difference threshold, the temperature distribution within the battery pack is further checked; then, the temperature difference between single cells within each battery pack is obtained. If the first cell temperature difference is greater than or equal to the first single-pack temperature difference threshold, the analysis and regulation of the temperature difference are further carried out between and within battery layers; the temperature difference between the upper and lower layers of the above single cell is measured; if the first inter-layer temperature difference is greater than or equal to the first inter-layer temperature difference threshold, the corresponding functional components are used to reduce the above inter-layer temperature difference of the above single cell. Exactly because the inter-layer temperature difference is considered, the judgment accuracy is improved, and further, the problem that the temperature control of the vehicle's entire battery system in the existing solution only considers the temperature difference between battery packs, resulting in a low judgment accuracy and being unable to effectively reduce the system temperature difference, is solved.

[0086] In an embodiment of the present application, the above device further includes: a third acquisition unit for, after using the corresponding functional components to reduce the above inter-layer temperature difference of the above single cell, acquiring the above inter-layer temperature difference of the above single cell again to obtain a second inter-layer temperature difference; a fourth acquisition unit for, when the absolute value of the above second inter-layer temperature difference is less than or equal to the second inter-layer temperature difference threshold, acquiring the difference between the maximum temperature difference between adjacent above single cells in the above battery pack and the minimum temperature difference between adjacent above single cells in the above battery pack again to obtain a second cell temperature difference, where the above second inter-layer temperature difference threshold is less than the above first inter-layer temperature difference threshold; a third processing unit for determining whether to stop using the above corresponding functional components to reduce the above inter-layer temperature difference of the above single cell according to the magnitude of the above second cell temperature difference; a fifth acquisition unit for, when it is determined to stop using the above corresponding functional components to reduce the above inter-layer temperature difference of the above single cell, acquiring the system temperature difference of the above vehicle's entire battery system again to obtain a second system temperature difference; a fourth processing unit for, when the absolute value of the above second system temperature difference is less than or equal to the second system temperature difference threshold, controlling the compressor to continue with liquid cooling operation, where the above second system temperature difference threshold is less than the above first system temperature difference threshold.

[0087] In an embodiment of the present application, the third processing unit includes: a first processing module for determining to stop using the above corresponding functional components to reduce the above inter-layer temperature difference of the above single cell when the absolute value of the above second cell temperature difference is less than or equal to the second single-pack temperature difference threshold, where the above second single-pack temperature difference threshold is less than the above first single-pack temperature difference threshold; a second processing module for determining that there is no need to stop using the above corresponding functional components to reduce the above inter-layer temperature difference of the above single cell when the absolute value of the above second cell temperature difference is greater than the above second single-pack temperature difference threshold.

[0088] In an embodiment of the present application, the above device further includes: a sixth acquisition unit configured to acquire the temperature difference within the first layer when the absolute value of the above first battery temperature difference is greater than or equal to the above first single-cell temperature difference threshold, where the temperature difference within the first layer is the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within a single layer of the above single cell; a fifth processing unit configured to control the heating module to heat the above single layer of the above single cell when the absolute value of the temperature difference within the first layer is greater than or equal to the temperature difference threshold within the first layer, and acquire again the difference between the maximum temperature difference and the minimum temperature difference among the above acquisition points within the above single layer of the above single cell to obtain the temperature difference within the second layer; a seventh acquisition unit configured to acquire the above second battery temperature difference when the absolute value of the temperature difference within the second layer is less than or equal to the temperature difference threshold within the second layer, where the temperature difference threshold within the second layer is less than the temperature difference threshold within the first layer.

[0089] In an embodiment of the present application, the second processing unit includes at least one of the following: a third processing module configured to increase the opening degree of the flow valve to adjust the inter-layer flow rate of the liquid cooling pipe of the above vehicle battery system within the above single cell, where the flow valve is located between the upper layer and the lower layer within the above single cell; a fourth processing module configured to control the heating module to heat the above single cell to perform heating compensation on the above upper layer and the above lower layer of the above single cell, where the heating module is located between the upper layer and the lower layer within the above single cell.

[0090] In an embodiment of the present application, the above device further includes: an eighth acquisition unit configured to acquire a plurality of temperatures of the above battery pack within a preset time period to obtain a plurality of battery pack temperatures before acquiring the system temperature difference of the above vehicle battery system to obtain the first system temperature difference; a sixth processing unit configured to determine the current battery pack acquisition temperature of the above battery pack according to the magnitudes of all the battery pack temperatures; a seventh processing unit configured to determine the maximum temperature difference and the minimum temperature difference among the above battery packs according to the above current battery pack acquisition temperatures of all the above battery packs.

[0091] In an embodiment of the present application, the sixth processing unit includes: a fifth processing module for sorting all the battery pack temperatures in chronological order to obtain a battery pack temperature sequence; a sixth processing module for determining the battery pack temperature as the currently acquired battery pack temperature when all the battery pack temperatures in the battery pack temperature sequence are the same; a seventh processing module for determining the first battery pack temperature in the battery pack temperature sequence as the currently acquired battery pack temperature when the first battery pack temperature in the battery pack temperature sequence is different from all other battery pack temperatures in the battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are also different from each other; an eighth processing module for determining the other battery pack temperatures except the first battery pack temperature as the currently acquired battery pack temperature when the first battery pack temperature in the battery pack temperature sequence is different from all other battery pack temperatures in the battery pack temperature sequence except the first battery pack temperature, and the other battery pack temperatures except the first battery pack temperature are the same.

[0092] The control device of the above vehicle-mounted battery system includes a processor and a memory. The first acquisition unit, the first processing unit, the second acquisition unit, the second processing unit, etc. are all stored in the memory as program units, and the corresponding functions are implemented by the processor executing the program units stored in the memory. The above modules are all located in the same processor; or, the above modules are respectively located in different processors in any combination form.

[0093] The processor contains a kernel, and the kernel retrieves the corresponding program units from the memory. One or more kernels can be set, and by adjusting the kernel parameters, the problem that the temperature control of the vehicle-mounted battery system in the existing solution only considers the temperature difference between battery packs, resulting in low judgment accuracy and inability to effectively reduce the system temperature difference, can be solved.

[0094] The memory may include non-permanent memory in a computer-readable medium, forms such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM), and the memory includes at least one storage chip.

[0095] The embodiment of the present invention provides a computer-readable storage medium. The computer-readable storage medium includes a stored program, and when the program runs, it controls the device where the computer-readable storage medium is located to execute the control method of the vehicle-mounted battery system.

[0096] The embodiment of the present invention provides a processor. The processor is used to run a program, and when the program runs, it executes the control method of the vehicle-mounted battery system.

[0097] An embodiment of the present invention provides a device, which includes a processor, a memory, and a program stored on the memory and executable on the processor. When the processor executes the program, at least the following steps are implemented: when the compressor of the vehicle battery system starts to perform liquid cooling work, obtain the system temperature difference of the vehicle battery system to obtain a first system temperature difference. The liquid cooling work means using the compressor to cool each battery pack in the vehicle battery system. The system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference among the battery packs in the vehicle battery system; when the absolute value of the first system temperature difference is greater than or equal to the first system temperature difference threshold, control the compressor to stop working, and obtain the difference between the maximum temperature difference and the minimum temperature difference among adjacent single cells in the battery pack to obtain a first battery temperature difference; when the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the interlayer temperature difference of the single cell to obtain a first interlayer temperature difference. The interlayer temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the upper layer and the lower layer of the single cell; when the absolute value of the first interlayer temperature difference is greater than or equal to the first interlayer temperature difference threshold, use a corresponding functional component to reduce the interlayer temperature difference of the single cell. The corresponding functional component is a component for adjusting the interlayer temperature difference of the single cell. The device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0098] The present application also provides a computer program product which, when executed on a data processing device, is adapted to execute a program initialized with at least the following method steps: When the compressor of the vehicle battery system starts liquid cooling operation, obtain the system temperature difference of the above vehicle battery system to obtain a first system temperature difference. The above liquid cooling operation means that the compressor is used to cool each battery pack in the above vehicle battery system. The above system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the battery packs in the above vehicle battery system; When the absolute value of the above first system temperature difference is greater than or equal to the first system temperature difference threshold, control the above compressor to stop working, and obtain the difference between the maximum temperature difference between adjacent single cells in the above battery pack and the minimum temperature difference between the adjacent single cells in the above battery pack to obtain a first battery temperature difference; When the absolute value of the above first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the interlayer temperature difference of the above single cell to obtain a first interlayer temperature difference. The above interlayer temperature difference is the difference between the maximum temperature difference between the upper and lower layers of the above single cell and the minimum temperature difference between the upper and lower layers of the above single cell; When the absolute value of the above first interlayer temperature difference is greater than or equal to the first interlayer temperature difference threshold, use a corresponding functional component to reduce the above interlayer temperature difference of the above single cell. The above corresponding functional component is a component for adjusting the above interlayer temperature difference of the above single cell.

[0099] The present application also provides a control system for a vehicle battery system. The system includes: one or more processors, a memory, and one or more programs. Among them, the above one or more programs are stored in the above memory and are configured to be executed by the above one or more processors. The above one or more programs include those for executing any one of the above methods. First, monitor the system temperature difference, that is, the temperature difference between the battery packs in the entire battery system; If the first system temperature difference is greater than or equal to the first system temperature difference threshold, further check the temperature distribution within the battery pack; Then, obtain the temperature difference between the single cells in each battery pack. If the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, further analyze and control the temperature difference between the battery layers and within the layers; Measure the temperature difference between the upper and lower layers of the above single cell; If the first interlayer temperature difference is greater than or equal to the first interlayer temperature difference threshold, use a corresponding functional component to reduce the above interlayer temperature difference of the above single cell. It is precisely because the interlayer temperature difference is considered that the judgment accuracy is improved, and further the problem that the temperature control of the vehicle battery system in the existing solution only considers the temperature difference between the battery packs, resulting in a low judgment accuracy and an inability to effectively reduce the system temperature difference, is solved.

[0100] Obviously, those skilled in the art should understand that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. They can be implemented by program code executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately made into individual integrated circuit modules, or multiple modules or steps among them can be made into a single integrated circuit module for implementation. In this way, the present invention is not limited to any specific combination of hardware and software.

[0101] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or a combination of multiple flows and / or blocks

[0103] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in Figure 1 one or more of the flows Figure 1 or a combination of multiple flows and / or blocks

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the functions in the flowFigure 1 one or more processes and / or blocks Figure 1 steps of functions specified in one or more blocks

[0105] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0106] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0107] Computer-readable media includes permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, disk storage or other magnetic storage devices, or any other non-transitory media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0108] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0109] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method for a vehicle battery system, characterized in that, Including: When the compressor of the vehicle's battery system starts liquid cooling operation, obtain the system temperature difference of the vehicle's battery system to get the first system temperature difference. The liquid cooling operation means using the compressor to cool down each battery pack in the vehicle's battery system. The system temperature difference is the difference between the maximum temperature difference and the minimum temperature difference among the battery packs in the vehicle's battery system; When the absolute value of the first system temperature difference is greater than or equal to the first system temperature difference threshold, control the compressor to stop working, and obtain the difference between the maximum temperature difference and the minimum temperature difference among adjacent single cells in the battery pack to get the first battery temperature difference; When the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the inter-layer temperature difference of the single cell to get the first inter-layer temperature difference. The inter-layer temperature difference is the difference between the maximum temperature difference and the minimum temperature difference between the upper layer and the lower layer of the single cell; When the absolute value of the first inter-layer temperature difference is greater than or equal to the first inter-layer temperature difference threshold, use the corresponding functional component to reduce the inter-layer temperature difference of the single cell. The corresponding functional component is the component that adjusts the inter-layer temperature difference of the single cell.

2. The method according to claim 1, characterized in that, After using the corresponding functional component to reduce the inter-layer temperature difference of the single cell, the method further includes: Obtain the inter-layer temperature difference of the single cell again to get the second inter-layer temperature difference; When the absolute value of the second inter-layer temperature difference is less than or equal to the second inter-layer temperature difference threshold, obtain the difference between the maximum temperature difference and the minimum temperature difference among adjacent single cells in the battery pack again to get the second battery temperature difference. The second inter-layer temperature difference threshold is less than the first inter-layer temperature difference threshold; Determine whether to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell according to the magnitude of the second battery temperature difference; When it is determined to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell, obtain the system temperature difference of the vehicle's battery system again to get the second system temperature difference; When the absolute value of the second system temperature difference is less than or equal to the second system temperature difference threshold, control the compressor to continue liquid cooling operation. The second system temperature difference threshold is less than the first system temperature difference threshold.

3. The method according to claim 2, wherein Determining whether to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell according to the magnitude of the second battery temperature difference includes: When the absolute value of the second battery temperature difference is less than or equal to the second single-pack temperature difference threshold, determine to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell. The second single-pack temperature difference threshold is less than the first single-pack temperature difference threshold; When the absolute value of the second battery temperature difference is greater than the second single-pack temperature difference threshold, determine that there is no need to stop using the corresponding functional component to reduce the inter-layer temperature difference of the single cell.

4. The method according to claim 2, characterized in that The method further includes: When the absolute value of the first battery temperature difference is greater than or equal to the first single-pack temperature difference threshold, obtain the temperature difference within the first layer, where the temperature difference within the first layer is the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within the single layer of the single battery; When the absolute value of the temperature difference within the first layer is greater than or equal to the temperature difference threshold within the first layer, control the heating module to heat the single layer of the single battery, and obtain again the difference between the maximum temperature difference and the minimum temperature difference among the acquisition points within the single layer of the single battery, to obtain the temperature difference within the second layer; When the absolute value of the temperature difference within the second layer is less than or equal to the temperature difference threshold within the second layer, obtain the second battery temperature difference, where the temperature difference threshold within the second layer is less than the temperature difference threshold within the first layer.

5. The method according to claim 1, characterized in that, Using the corresponding functional components to reduce the inter-layer temperature difference of the single battery includes at least one of the following: Increase the opening degree of the flow valve to adjust the inter-layer flow of the liquid cooling pipe of the vehicle battery system within the single battery, where the flow valve is located between the upper layer and the lower layer within the single battery; Control the heating module to heat the single battery to perform heating compensation on the upper layer and the lower layer of the single battery, where the heating module is located between the upper layer and the lower layer within the single battery.

6. The method according to claim 1, characterized in that, Before obtaining the system temperature difference of the vehicle battery system to obtain the first system temperature difference, it includes: Obtain multiple temperatures of the battery pack within a preset time period to obtain multiple battery pack temperatures; Determine the current battery pack acquisition temperature of the battery pack according to the magnitudes of all the battery pack temperatures; Determine the maximum temperature difference and the minimum temperature difference among the battery packs according to the current battery pack acquisition temperatures of all the battery packs.

7. The method according to claim 6, characterized in that, Determining the current battery pack acquisition temperature of the battery pack according to the magnitudes of all the battery pack temperatures includes: Sort all the battery pack temperatures in chronological order to obtain a battery pack temperature sequence; When all the battery pack temperatures in the battery pack temperature sequence are the same, determine the battery pack temperature as the current battery pack acquisition temperature; When the first battery pack temperature in the battery pack temperature sequence is different from all the other battery pack temperatures except the first battery pack temperature in the battery pack temperature sequence, and the other battery pack temperatures except the first battery pack temperature are also different from each other, determine the first battery pack temperature as the current battery pack acquisition temperature; When the first battery pack temperature in the battery pack temperature sequence is different from all the other battery pack temperatures except the first battery pack temperature in the battery pack temperature sequence, and the other battery pack temperatures except the first battery pack temperature are the same, determine the other battery pack temperatures except the first battery pack temperature as the current battery pack acquisition temperature.

8. A control device for a vehicle battery system, characterized in that, It includes: A first acquisition unit, configured to obtain a system temperature difference of the vehicle battery system, so as to obtain a first system temperature difference, when a compressor of the vehicle battery system starts to perform liquid cooling work, where the liquid cooling work indicates that the compressor is used to cool each battery pack in the vehicle battery system, and the first system temperature difference is a difference between a maximum value of temperature differences between the battery packs in the vehicle battery system and a minimum value of the temperature differences between the battery packs; A first processing unit, configured to control the compressor to stop working when an absolute value of the first system temperature difference is greater than or equal to a first system temperature difference threshold, and obtain a difference between a maximum value of temperature differences between adjacent single cells in the battery pack and a minimum value of the temperature differences between the adjacent single cells in the battery pack, so as to obtain a first battery temperature difference; A second acquisition unit, configured to obtain an interlayer temperature difference of the single cell, so as to obtain a first interlayer temperature difference, when the absolute value of the first battery temperature difference is greater than or equal to a first single-pack temperature difference threshold, where the interlayer temperature difference is a difference between a maximum value of temperature differences between an upper layer and a lower layer of the single cell and a minimum value of the temperature differences between the upper layer and the lower layer of the single cell; A second processing unit, configured to use a corresponding functional component to reduce the interlayer temperature difference of the single cell when the absolute value of the first interlayer temperature difference is greater than or equal to a first interlayer temperature difference threshold, where the corresponding functional component is a component for adjusting the interlayer temperature difference of the single cell.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, where, when the program runs, it controls a device where the computer-readable storage medium is located to execute the method according to any one of claims 1 to 7.

10. A control system for a vehicle battery system, characterized in that, Including: One or more processors, a memory, and one or more programs, where the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include those for executing the method according to any one of claims 1 to 7.

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